Study of impact on helicopter blade

Abstract

RésuméLe présent article propose une étude de l'impact de structures similaires à des tronçons de pales d'hélicoptère. Ces structures composites complexes, fabriquées au laboratoire sont impactées par une bille en acier de 125 g à des vitesses d'impact variant de 30 à 130 m/s. Les essais sont enregistrés par une caméra rapide qui permet une acquisition de 120000 images/seconde. Cela a permis de mettre en évidence la cinématique de l'impact et de définir la chronologie des différents mécanismes d'endommagements. Un travail de modélisation est aussi présenté. Différentes stratégies de modélisation EF, à l'échelle macroscopique, permettent ainsi de modéliser ces phénomènes avec des densités de maillage qui ne sont pas pénalisantes lors d'un calcul sur une structure réelle. AbstractThis article presents a study of damage in structures similar to sections of helicopter blades subjected to an impact. These complex composite structures manufactured in the laboratory were impacted by a steel ball of 125 g at impact speeds ranging from 30 to 130 m / s. The tests are recorded by a camera that allows acquisitions of 120,000 fps. This permitted to highlight the kinematics of the impact and to define the sequence of damage's mechanisms. An FE model is also presented. It allows modeling the experimentally observed damage. The mesh density is low and can be used for a calculation on a real structure Mots Clés : IMPACT, COMPOSITE, PALES, MEF

An experimental method dedicated to the dynamic characterization of structural adhesives under drop weight conditions

“…Two test campaigns were carried out: (1) under the crosshead of a 100 kN tensile testing machine Instron ® 8862 to obtain low strain rates and 2 (Figs. 7b & d).…”

“…Therefore, it is hence necessary to characterize their dynamic mechanical behaviour in order to implement calculation models and to ensure users safety. The study of impact on helicopter blade proposed by Tawk in [1] is a good illustration of this problematic.…”

Crashworthy design and energy absorption mechanisms for helicopter structures: A systematic literature review

“…The initiation and growth of the damage in crucial components were captured, and a parametric investigation was conducted to study the impact damage behaviors. Tawk et al [223] conducted experimental tests and numerical simulations to study the ballistic behaviors of a helicopter blade subjected to a frontal impact which is shown in Fig. 30.…”

Experimental results of medium velocity impact tests for reinforced foam core braided composite structures

“…In Rivallant et al [2] foam-skin debonding was found to start the initiation of damage under drop weight tests. In Tawk et al [3] composite structures similar to helicopter blades were impacted by a steel ball shot at a velocity of up to 140 m/s using a gas gun and the authors identified the following damage scenario: damage of the front edge, skin-foam delamination, damage of the roving and penetration.…”